JP2002142483A - Control method and controller of synchronous motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize reduction in size and maximum efficiency of a synchronous motor by utilizing the voltage and current to the maximum while preventing occurrence of trip. SOLUTION: The controller for a synchronous motor comprises a position/ speed detecting section 4 outputting the rotational position and rotational speed of the rotor of a synchronous motor 3 based on the motor current and motor voltage, a speed control section 5 performing speed control by receiving a speed from the position/speed detecting section 4 and an external speed command as inputs and outputting a current command, a phase control section 6 receiving a current command and an external phase command as inputs and outputting a current amplitude command, a current control section 7 receiving a current amplitude command, a motor current and a rotational position as inputs and outputting a voltage command being fed to an inverter 2, a maximum phase table 8 receiving a speed from the position/speed detecting section 4 and a voltage command as inputs and outputting a corresponding maximum current phase, and a phase limit section 9 for limiting the phase command to be fed to the phase control section 6 based on the maximum current phase.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a synchronous motor control method for controlling a synchronous motor by supplying an output voltage of an inverter to the synchronous motor, and an apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a synchronous motor controller for controlling a synchronous motor by supplying an output voltage of an inverter to the synchronous motor.

[0003] Such a synchronous motor control device (1) controls an inverter by performing overmodulation, using voltage control and voltage phase control together, and supplying an inverter output voltage to control the synchronous motor. (2) controlling the inverter without performing overmodulation, using the current control and the current phase control together, and controlling the synchronous motor by supplying the inverter output voltage;
(3) It has been proposed to control a synchronous motor by switching between voltage control and current control to control an inverter and supplying an inverter output waveform. Also, (4)
In the synchronous motor control device of (2), there has been proposed a device that limits the maximum value of the current phase controlled by the current phase control to an appropriate value. For example, JP-A-8-32227
In the brushless DC motor control device disclosed in Japanese Patent Application Laid-Open No. 9-1997, the maximum phase is set according to the required torque.

[0004]

When the synchronous motor control device of the above (1) is employed, the output voltage of the inverter can be used to the maximum, but a current trip occurs at the time of overload. There is a disadvantage that the inverter output current cannot be used to the maximum.

When the synchronous motor control device of the above (2) is adopted, the occurrence of a current trip can be prevented beforehand, but there is a disadvantage that the inverter output voltage cannot be used to the maximum. In other words, there is a disadvantage that the efficiency cannot be sufficiently increased.

In the case where the synchronous motor control device of the above (3) is employed, there is a disadvantage when the synchronous motor control device of the above (1) is employed in accordance with the switching, and when the synchronous motor control device of the above (2) is employed. In addition, a configuration for performing voltage control and a configuration for performing current control are required, and the configuration is complicated.

When the synchronous motor control device of the above (4) is employed, the maximum value of the current phase is limited only by an appropriate value, so that the capabilities of the synchronous motor and the inverter are utilized to the maximum. There is an inconvenience that you cannot do it.
Further explanation will be given.

[0008] Since the synchronous motor cannot be brought into a state capable of generating the maximum torque, it is necessary to increase the size of the synchronous motor more than necessary. In addition, when high-speed rotation is performed, it is necessary to employ a motor with a low induced voltage, so the drive current increases. When the compressor is driven by a synchronous motor, the compressor rating (medium speed range) Efficiency is reduced. Furthermore, because the current phase is not properly limited, if the current phase exceeds the true limit value, the synchronous motor will stall, causing inconveniences such as tripping, drastic reduction in efficiency, and failure to achieve the operating range. Would.

Further description will be given.

Conventionally, in controlling a synchronous motor, no maximum torque condition under a voltage constraint has been disclosed, and in servo applications, it is not allowed to perform speed droop control. Since the margin design for providing a margin for the current was fundamental, it was impossible at all to control the synchronous motor under the maximum torque condition. Even in applications other than servos, margin design is common sense, and it has never been possible to control a synchronous motor under the maximum torque condition. In other words, it was not possible to utilize the maximum capacity of the synchronous motor, such as maximum acceleration, maximum torque, etc. For this reason, if the margin is exceeded, the synchronous motor will stall, which will result in trips, reduced efficiency, and failure to reach the operating range.

Further, when the inverter output voltage is sufficiently higher than the motor induced voltage, torque control is performed by the motor current, and when the motor voltage cannot be increased due to the motor induced voltage during high-speed rotation. It has been known that the magnetic flux is weakened by advancing the current phase, and the motor current is increased to further rotate the motor at a higher speed. However, no method has been proposed to extract the maximum capacity of the motor using these, nor has any method been proposed to prevent the divergence of the control system when a command exceeding the capacity is given instantaneously. . Therefore, it is impossible to use up the full capacity of the motor inverter while maintaining good controllability (high response speed, high efficiency).

Further, since it is considered that the current control system diverges when the inverter output voltage reaches the limit value, when the inverter output voltage is used near the limit value,
Current control cannot be performed, and as a result, inconveniences such as tripping and divergence of the control system occur.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and makes it possible to make maximum use of the capacity of a synchronous motor and to make the most of the capacity of an inverter while ensuring high controllability. It is an object of the present invention to provide a synchronous motor control method and a synchronous motor control method capable of performing tripless and current control while maximizing use of an inverter output voltage.

[0014]

According to a first aspect of the present invention, in controlling a synchronous motor by supplying an output voltage of an inverter to the synchronous motor, an upper limit value of a current phase is set for each instant. This is a method of setting the inverter output voltage at that time to a phase at which the motor torque is maximized or in the vicinity thereof.

According to a second aspect of the present invention, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set to the maximum output voltage of the inverter for each rotation speed. This is a method of setting the phase at or near the phase where the motor torque is maximized.

According to a third aspect of the present invention, there is provided a synchronous motor control method in which an upper limit value of a current phase is changed at least in response to a rotation speed.

According to a fourth aspect of the present invention, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set at the maximum output voltage of the inverter at the highest speed. This is a method in which the torque is set to a phase at which the torque is maximized or in the vicinity thereof.

In the synchronous motor control method according to the present invention, when the synchronous motor is controlled by supplying the output voltage of the inverter to the synchronous motor, the limit value of the current phase and the inverter output current are limited for each required torque. This is a method of setting the maximum phase, the minimum phase, or the vicinity thereof.

According to a sixth aspect of the present invention, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set for each instant. 2. A method of selecting the smallest upper limit value from the upper limit values set by claims 4 and 5.

In the synchronous motor control method according to the present invention, the lower limit value of the current phase is set to a current phase at which the efficiency or the torque is maximized or a vicinity thereof, and the smallest current phase among the current phases capable of outputting the required torque is set. This is a method of driving a synchronous motor by phase.

The synchronous motor control method according to claim 8 is a method of driving a compressor for an air conditioner by the synchronous motor.

A synchronous motor control method according to a ninth aspect is a method in which a permanent magnet motor is employed as the synchronous motor, and the upper limit value of the current phase is set to approximately 60 to 80 degrees.

According to a tenth aspect of the present invention, in controlling the permanent magnet motor by supplying the output voltage of the inverter to the permanent magnet motor, the output voltage of the inverter reaches a limit value as the rotation speed increases. In this method, the current phase is advanced in response to this, and the speed droop control is performed in response to reaching a predetermined current phase limit value or a current limit value.

In the synchronous motor control method according to the present invention, in controlling the permanent magnet motor by supplying the output voltage of the inverter to the permanent magnet motor, the output voltage of the inverter reaches a limit value as the number of revolutions increases. In this method, the current phase is advanced in response to this, and the internal state of the speed control means is maintained in a state immediately before reaching the limit value in response to reaching a predetermined current phase limit value or a current limit value.

According to a twelfth aspect of the present invention, when the inverter output voltage has a margin with respect to the output voltage limit value, a desired voltage waveform is output from the inverter, and the inverter output voltage approaches the output voltage limit value. This is a method in which the output voltage waveform from the inverter is brought closer to the output voltage waveform having a high voltage utilization rate in response to this.

A synchronous motor control method according to a thirteenth aspect is a method in which a sine wave is adopted as the desired voltage waveform.

[0027] A synchronous motor control method according to claim 14 is a method in which a rectangular wave is adopted as the output voltage waveform having a high voltage utilization factor.

A synchronous motor control method according to claim 15 is a method of driving a compressor by a permanent magnet motor.

In the synchronous motor control method according to the present invention, when the synchronous motor is controlled by supplying the output voltage of the inverter to the synchronous motor, the motor current is controlled regardless of whether the inverter output voltage amplitude is limited or not. How to control.

According to a seventeenth aspect of the present invention, in the synchronous motor control method, the motor current control is performed by increasing a motor terminal voltage command value in response to a small motor current, and controlling the motor terminal voltage in response to a large motor current. This is a method performed by reducing the command value.

A synchronous motor control method according to claim 18 is a method for controlling an inverter to compensate for a decrease in torque due to the voltage limitation.

A synchronous motor control method according to a nineteenth aspect is a method for compensating the decrease in the torque by compensating the decrease in the amplitude of the fundamental wave component of the phase voltage command due to the voltage limitation.

In the synchronous motor control method according to the present invention, in response to the degree of overmodulation for increasing the voltage utilization rate exceeding a predetermined value, the current phase is adjusted so that the degree of overmodulation becomes a predetermined value. How to control.

A synchronous motor control method according to claim 21 is a method in which a permanent magnet motor having a permanent magnet embedded inside a rotor is used as the synchronous motor.

A synchronous motor control method according to claim 22 is a method of driving a compressor by the synchronous motor.

According to a twenty-third aspect of the present invention, there is provided a synchronous motor control apparatus for controlling a synchronous motor by supplying an output voltage of an inverter to the synchronous motor. And inverter control means for setting the phase at or near the phase at which the motor torque is maximized.

According to a twenty-fourth aspect of the present invention, the synchronous motor control device controls the synchronous motor by supplying the output voltage of the inverter to the synchronous motor. And inverter control means for setting the phase at or near the phase at which the motor torque is maximized.

According to a twenty-fifth aspect of the present invention, the synchronous motor control device employs, as the inverter control means, one that changes an upper limit value of a current phase at least in response to a rotation speed.

According to a twenty-sixth aspect of the present invention, the synchronous motor control device controls the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, wherein the upper limit value of the current phase is set at the maximum output voltage of the inverter at the highest speed. It includes inverter control means for setting the phase at or near the phase at which the motor torque is maximized.

According to a twenty-seventh aspect of the present invention, there is provided a synchronous motor control device for controlling a synchronous motor by supplying an output voltage of an inverter to the synchronous motor, wherein a current phase limit value is limited for each required torque. Inverter control means for setting the maximum phase and the minimum phase to be set, or the vicinity thereof.

A synchronous motor control apparatus according to claim 28, wherein the synchronous motor is controlled by supplying the output voltage of the inverter to the synchronous motor, wherein the upper limit value of the current phase is set for each instant. Claim 24, Claim 2
6. The inverter control means for selecting the smallest upper limit value from the upper limit values set by claim 27.

According to a twenty-ninth aspect of the present invention, in the synchronous motor control device, as the inverter control means, a lower limit value of a current phase is set to a current phase that maximizes efficiency or torque, or a vicinity thereof, and a current capable of outputting a required torque. The one that controls the inverter to drive the synchronous motor with the smallest current phase among the phases is adopted.

According to a thirtieth aspect of the present invention, a synchronous motor control device that drives a compressor for an air conditioner is used as the synchronous motor.

According to a thirty-first aspect of the present invention, the synchronous motor control device employs a permanent magnet motor as the synchronous motor, and the inverter control means sets the upper limit of the current phase to approximately 60 degrees to 8 degrees.
What is set to 0 degrees is adopted.

A synchronous motor control device according to claim 32 controls the permanent magnet motor by supplying the output voltage of the inverter to the permanent magnet motor, wherein the output voltage of the inverter reaches a limit value as the rotation speed increases. An inverter control means for advancing the current phase in response to the reaching and performing speed droop control in response to reaching a predetermined current phase limit value or a current limit value.

According to a third aspect of the present invention, there is provided a synchronous motor control apparatus for controlling a permanent magnet motor by supplying an output voltage of the inverter to the permanent magnet motor. Inverter control means for advancing the current phase in response to the reaching, and for holding the internal state of the speed control means in the state immediately before reaching the limit value in response to reaching the predetermined current phase limit value or the current limit value. Including.

According to a thirty-fourth aspect of the present invention, as the inverter control means, when the inverter output voltage has a margin with respect to the output voltage limit value, a desired voltage waveform is output from the inverter, and the inverter output voltage is output. In this case, the output voltage waveform from the inverter is made closer to the output voltage waveform having a high voltage utilization rate in response to approaching the voltage limit value.

A synchronous motor control device according to a thirty-fifth aspect employs, as the inverter control means, one having a sine wave having the desired voltage waveform.

A synchronous motor control device according to a thirty-sixth aspect employs, as the inverter control means, one that uses a rectangular wave as the output voltage waveform having a high voltage utilization factor.

A synchronous motor control device according to a thirty-seventh aspect employs a permanent magnet motor that drives a compressor.

A synchronous motor control device according to a thirty-eighth aspect controls a synchronous motor by supplying an output voltage of an inverter to the synchronous motor, wherein the motor current is controlled regardless of whether the inverter output voltage amplitude is limited or not. Inverter control means for controlling the inverter to control the power supply.

A synchronous motor control device according to a thirty-ninth aspect is characterized in that the inverter control means controls the motor current.
In this case, the motor terminal voltage command value is increased in response to a small motor current, and the motor terminal voltage command value is decreased in response to a large motor current.

The synchronous motor control device according to claim 40 employs, as the inverter control means, one that controls an inverter to compensate for a decrease in torque due to the voltage limitation.

The synchronous motor control device according to claim 41 employs, as said inverter control means, a means for compensating for a decrease in said torque by compensating for a decrease in amplitude of a fundamental wave component of a phase voltage command due to voltage limitation. Is what you do.

A synchronous motor control device according to claim 42, wherein the inverter control means controls the current phase so that the degree of overmodulation becomes a predetermined value in response to the degree of overmodulation exceeding a predetermined value. Is used.

A synchronous motor control device according to claim 43 employs a permanent magnet motor having a permanent magnet embedded inside a rotor as the synchronous motor.

A synchronous motor control device according to claim 44 employs a synchronous motor control device that drives a compressor.

[0058]

According to the synchronous motor control method of the first aspect, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set as follows.
At each instant, the inverter output voltage is set at or near the phase that maximizes the motor torque at the inverter output voltage at that time, so the current phase is advanced to increase the maximum rotation speed, or the voltage phase or When operating the current phase, operation near the maximum torque that can be generated by the synchronous motor can be performed. As a result,
The occurrence of trips can be prevented beforehand, the voltage and current can be used to the maximum, and the maximum efficiency can be achieved by downsizing and optimal tuning of the synchronous motor.

According to the synchronous motor control method of the second aspect,
In controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set at or near the phase at which the motor torque is maximized at the inverter maximum output voltage for each rotation speed. Therefore, the synchronous motor can be controlled using the upper limit of the current phase set for each speed, and the current phase during the field weakening control at high speed can be kept below the upper limit. As a result, it is possible to prevent the occurrence of a trip, and to make the most of the voltage and current,
As a result, the size of the synchronous motor can be reduced, and the maximum efficiency can be achieved by optimal tuning.

According to the synchronous motor control method of claim 3,
Since the upper limit value of the current phase is changed at least in response to the rotation speed, the same operation as the first or second aspect can be achieved.

According to the synchronous motor control method of claim 4,
In controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set at or near the phase at which the motor torque is maximized at the inverter maximum output voltage at the highest speed. As a result, it is possible to simplify the process, prevent trips from occurring, maximize the use of voltage and current, and achieve maximum efficiency by miniaturizing the synchronous motor and optimal tuning. Can be.

According to the synchronous motor control method of claim 5,
In controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the current phase limit value is set to a maximum phase and a minimum phase in which the inverter output current is limited for each required torque, or a combination thereof. Since the values are set close to each other, a decrease in torque can be prevented, and the current phase can be controlled to the maximum. As a result, the occurrence of a trip can be prevented beforehand, the voltage and the current can be used to the maximum, and the size of the synchronous motor can be reduced, and the maximum efficiency can be realized by the optimal tuning.

According to the synchronous motor control method of claim 6,
In controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the upper limit value of the current phase is set for each instant according to claims 1, 2, 4, and 5. Since the smallest upper limit value is selected from the upper limit values, limiting the current phase by the selected upper limit value can prevent trips from occurring and maximize the use of voltage and current. As a result, the size of the synchronous motor can be reduced, and the maximum efficiency can be achieved by optimal tuning.

According to the synchronous motor control method of claim 7,
Since the lower limit of the current phase is set at or near the current phase that maximizes efficiency or torque, the synchronous motor is driven with the smallest current phase among the current phases that can output the required torque. Can be controlled to a phase between the lower limit value and the upper limit value.
Accordingly, the same function as any one of claims 6 can be achieved.

According to the synchronous motor control method of claim 8,
Since the compressor for the air conditioner is driven by the synchronous motor, it is possible to cool the synchronous motor, which generates a large amount of heat during the field weakening control by the refrigerant, without considering heat radiation of the synchronous motor. The same operation as any one of the seventh aspect can be achieved.

According to the synchronous motor control method of claim 9,
Since a permanent magnet motor is employed as the synchronous motor and the upper limit of the current phase is set to approximately 60 degrees to 80 degrees, it is possible to obtain the maximum performance of the permanent magnet motor and realize good operation characteristics. In addition, the same function as the eighth aspect can be achieved.

According to the synchronous motor control method of the present invention, in controlling the permanent magnet motor by supplying the output voltage of the inverter to the permanent magnet motor, the output voltage of the inverter is limited to a limit value with an increase in the rotation speed. In response to reaching the current limit, the current phase is advanced, and the speed droop control is performed in response to reaching the predetermined current phase limit value or the current limit value. To prevent divergence of the control system. Then, the occurrence of a trip can be prevented beforehand, the voltage and the current can be used to the maximum, and the miniaturization of the synchronous motor and the maximum efficiency by the optimal tuning can be realized.

According to the synchronous motor control method of the present invention, in controlling the permanent magnet motor by supplying the output voltage of the inverter to the permanent magnet motor, the output voltage of the inverter is increased to a limit value as the rotation speed increases. In response to reaching the limit, the current phase is advanced, and in response to reaching the predetermined current phase limit value or the current limit value, the internal state of the speed control means is maintained at the state immediately before reaching the limit value. The divergence of the speed control system can be prevented.
In addition to preventing the occurrence of trips,
Voltage and current can be used to the fullest, and
The miniaturization of the synchronous motor and the maximum efficiency by the optimal tuning can be realized.

According to the synchronous motor control method of claim 12, when the inverter output voltage has a margin with respect to the output voltage limit value, a desired voltage waveform is output from the inverter,
In response to the inverter output voltage approaching the output voltage limit value, the output voltage waveform from the inverter approaches the output voltage waveform with a high voltage utilization factor. In addition to being able to achieve, the expansion of the high-speed operation range can be achieved, and the same operation as that of claim 10 or claim 11 can be achieved.

According to the synchronous motor control method of claim 13, since a sine wave is employed as the desired voltage waveform, noise and vibration due to harmonics can be easily suppressed. A similar effect can be achieved.

According to the synchronous motor control method of the fourteenth aspect, since a rectangular wave is adopted as the output voltage waveform having a high voltage utilization factor, it is possible to sufficiently expand the high-speed operation range. Claim 12 or Claim 13
The same operation as described above can be achieved.

According to the synchronous motor control method of claim 15, since the compressor is driven by the permanent magnet motor, noise and vibration can be reduced, and the motor can be driven at a high speed. The same operation as any one of the tenth to fourteenth aspects can be achieved.

According to the synchronous motor control method of the present invention, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, regardless of whether the inverter output voltage amplitude is limited or not, Since the current is controlled, the motor current can be controlled even when the current increases due to disturbance or the like at the time of voltage limitation. In addition to preventing the occurrence of trips, it is possible to make maximum use of voltage and current,
As a result, the size of the synchronous motor can be reduced, and the maximum efficiency can be achieved by optimal tuning.

According to the synchronous motor control method of the present invention, the motor current control is performed by increasing a motor terminal voltage command value in response to a small motor current, and responding to a large motor current in response to a large motor current. Since the reduction is performed by decreasing the terminal voltage command value, the same operation as that of claim 16 can be achieved.

According to the synchronous motor control method of the eighteenth aspect, since the inverter is controlled to compensate for the decrease in torque due to the voltage limitation, the torque before the current limitation can be maintained. The same operation as that of claim 16 or 17 can be achieved.

According to the synchronous motor control method of the nineteenth aspect, the reduction of the torque is compensated for by the reduction of the amplitude of the fundamental wave component of the phase voltage command due to the voltage limitation. The same operation as described above can be achieved.

According to the synchronous motor control method of the present invention, in response to the degree of overmodulation for increasing the voltage utilization rate exceeding a predetermined value, the current is controlled so that the degree of overmodulation becomes a predetermined value. Since the phase is controlled, it is possible to prevent the degree of overmodulation from becoming too large, and to achieve the same effect as any one of the sixteenth to nineteenth aspects.

According to the synchronous motor control method of the present invention, since a permanent magnet motor in which a permanent magnet is embedded in a rotor is employed as the synchronous motor, the field weakening effect is effectively used. In addition to the above, the same operation as any one of claims 9 to 20 can be achieved.

According to the synchronous motor control method of the present invention, since the compressor is driven by the synchronous motor, even if a sudden increase in the load occurs, the overcurrent causing damage to the synchronous motor and the inverter can be obtained. Can be prevented, and the same operation as any one of claims 16 to 21 can be achieved.

According to the synchronous motor control device of the present invention, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the inverter control means sets the upper limit value of the current phase for each instant. The phase can be set at or near the phase that maximizes the motor torque at the inverter output voltage at that time.

Therefore, when the current phase is advanced in order to obtain the maximum rotation speed, or when the voltage phase or the current phase is controlled in order to perform the speed control, the control can be performed with the maximum torque that can be generated by the synchronous motor. As a result, the occurrence of a trip can be prevented beforehand, the voltage and current can be utilized to the maximum, and the synchronous motor can be downsized and the maximum efficiency can be achieved by optimal tuning.

According to the synchronous motor control device of the present invention, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the inverter control means sets the upper limit value of the current phase for each rotation speed. To
At the inverter maximum output voltage, the phase can be set at or near the phase at which the motor torque is maximized.

Therefore, the synchronous motor can be controlled by using the upper limit of the current phase set for each speed, and the current phase in the field-weakening control at high speed can be kept below the upper limit. As a result, the occurrence of a trip can be prevented beforehand, the voltage and the current can be used to the maximum, and the size of the synchronous motor can be reduced, and the maximum efficiency can be realized by the optimal tuning.

In the synchronous motor control device according to the twenty-fifth aspect, since the inverter control means changes the upper limit value of the current phase at least in response to the rotational speed, the inverter control means may be employed. The same operation as that of the item 24 can be achieved.

In the synchronous motor control device according to the twenty-sixth aspect, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the inverter control means sets the upper limit value of the current phase at the time of the highest speed rotation. At the maximum inverter output voltage, or at a phase near the maximum motor torque.

Therefore, the current phase can be limited only for the transient change at the time of the maximum voltage and the maximum current phase. As a result, it is possible to simplify the configuration and prevent the occurrence of trips, to maximize the use of voltage and current, and to achieve maximum efficiency by downsizing the synchronous motor and optimal tuning. Can be.

In the synchronous motor control device according to claim 27, when controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the inverter control means sets the limit value of the current phase for each required torque. The maximum phase at which the inverter output current will be limited,
And the minimum phase, or the vicinity thereof.

Therefore, it is possible to prevent a decrease in torque and control the current phase to the maximum. As a result,
A trip can be prevented from occurring, and the voltage and the current can be used to the maximum extent. As a result, the size of the synchronous motor can be reduced, and the maximum efficiency can be achieved by optimal tuning.

According to the synchronous motor control device of the present invention, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, the inverter control means sets the upper limit value of the current phase for each instant. , 23, 24, 26, and 27, the smallest upper limit can be selected.

Therefore, by limiting the current phase by the selected upper limit, it is possible to prevent the occurrence of a trip beforehand, and to make the most of the voltage and the current. In addition, maximum efficiency can be achieved by optimal tuning.

According to the synchronous motor control apparatus of the present invention, as the inverter control means, the lower limit value of the current phase is set to the current phase at which the efficiency or the torque is maximized, or the vicinity thereof, and the required torque is output. Since the inverter which controls the inverter to drive the synchronous motor with the smallest current phase among the possible current phases is adopted, the current phase can be controlled to a phase between the lower limit value and the upper limit value. The same operation as any one of the twenty-third to twenty-eighth aspects can be achieved.

According to the synchronous motor control device of the present invention, since the synchronous motor that drives the compressor for the air conditioner is adopted as the synchronous motor, the synchronous motor can be cooled by the refrigerant, and the synchronous motor can be cooled. The same operation as any one of claims 23 to 29 can be achieved without special consideration of the heat radiation.

According to the synchronous motor control device of the present invention, a permanent magnet motor is employed as the synchronous motor, and the inverter control means sets the upper limit of the current phase to approximately 6%.
Because it adopts what is set at 0 degrees to 80 degrees,
A flat torque characteristic can be realized by extracting the maximum capacity of the permanent magnet motor, and the same operation as that of claim 30 can be achieved.

According to the synchronous motor control device of the present invention, in controlling the permanent magnet motor by supplying the output voltage of the inverter to the permanent magnet motor, the inverter control means controls the inverter by increasing the number of revolutions. The current phase is advanced in response to the output voltage reaching the limit value, and the speed droop control can be performed in response to reaching the predetermined current phase limit value or the current limit value.

Therefore, the divergence of the control system can be prevented by driving the permanent magnet motor below the current limit and the phase limit. Then, the occurrence of a trip can be prevented beforehand, the voltage and the current can be used to the maximum, and the miniaturization of the synchronous motor and the maximum efficiency by the optimal tuning can be realized.

According to the synchronous motor control device of the present invention, in controlling the permanent magnet motor by supplying the output voltage of the inverter to the permanent magnet motor, the inverter control means controls the inverter by increasing the rotation speed. In response to the output voltage reaching the limit value, the current phase is advanced, and in response to reaching the predetermined current phase limit value or the current limit value, the internal state of the speed control means is changed to a state immediately before reaching the limit value. Can be held.

Therefore, divergence of the speed control system can be prevented. Then, the occurrence of a trip can be prevented beforehand, the voltage and the current can be used to the maximum, and the miniaturization of the synchronous motor and the maximum efficiency by the optimal tuning can be realized.

In the synchronous motor control device according to the thirty-fourth aspect, the inverter control means outputs a desired voltage waveform from the inverter when the inverter output voltage has a margin with respect to the output voltage limit value. Adopts an output voltage waveform from the inverter that approaches the output voltage waveform having a high voltage utilization in response to approaching the output voltage limit value. In addition to the expansion of the high-speed operation range, the same operation as that of claim 32 or 33 can be achieved.

According to the synchronous motor control device of claim 35, since a sine wave having the desired voltage waveform is adopted as the inverter control means, noise and vibration due to harmonics can be easily suppressed. In addition to being able to
The same operation as the thirty-fourth aspect can be achieved.

According to the synchronous motor control device of claim 36, since the inverter control means adopts a rectangular wave as the output voltage waveform having the high voltage utilization rate, the high speed operation range can be sufficiently expanded. Can be achieved, and the same operation as that of claim 34 or claim 35 can be achieved.

According to the synchronous motor control device of claim 37, since a permanent magnet motor that drives a compressor is employed, noise and vibration can be reduced, and the motor can be driven at a high speed. In addition to the above, the same operation as any of claims 32 to 36 can be achieved.

In the synchronous motor control device according to claim 38, in controlling the synchronous motor by supplying the output voltage of the inverter to the synchronous motor, whether the inverter output voltage amplitude is limited by the inverter control means is determined. Regardless, the inverter can be controlled to control the motor current.

Therefore, the motor current can be controlled even when the current increases due to disturbance or the like at the time of voltage limitation. Then, the occurrence of a trip can be prevented beforehand, the voltage and the current can be used to the maximum, and the miniaturization of the synchronous motor and the maximum efficiency by the optimal tuning can be realized.

According to the synchronous motor control device of the present invention, the inverter control means controls the motor current by increasing the motor terminal voltage command value in response to the small motor current and increasing the motor current. In this case, the operation performed by decreasing the motor terminal voltage command value is adopted, so that the same operation as that of claim 38 can be achieved.

In the synchronous motor control device according to claim 40, since the inverter control means employs an inverter control means for controlling the inverter to compensate for a decrease in torque due to the voltage limitation, the inverter control means may be used before the current limitation. In addition to maintaining the torque, it is possible to achieve the same operation as that of the thirty-eighth or thirty-ninth aspect.

In the synchronous motor control device according to claim 41, the inverter control means compensates for the decrease in the torque by compensating for the decrease in the amplitude of the fundamental wave component of the phase voltage command due to the voltage limitation. Therefore, the same operation as the forty-third aspect can be achieved.

According to the synchronous motor control device of the present invention, as the inverter control means, the degree of overmodulation becomes a predetermined value in response to the degree of overmodulation exceeding a predetermined value. Since a device for controlling the current phase is employed, it is possible to prevent the degree of overmodulation from becoming too large, and to provide a method for controlling the current phase.
The same operation as any one of the first aspect can be achieved.

According to the synchronous motor control device of the present invention, a permanent magnet motor in which a permanent magnet is embedded in the rotor is used as the synchronous motor, so that the field weakening effect is effectively used. In addition to the above, the same operation as any one of claims 31 to 42 can be achieved.

According to the synchronous motor control device of claim 44, since the synchronous motor that drives the compressor is employed, even if a sudden increase in load occurs, the synchronous motor and the inverter may be damaged. In addition to preventing overcurrent that causes
3 can achieve the same operation as any of the above.

[0110]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a synchronous motor control method according to an embodiment of the present invention;

FIG. 1 is a block diagram showing one embodiment of the synchronous motor control device of the present invention.

This synchronous motor control device includes a converter 1a that receives an AC power supply 1 as an input and outputs DC power, an inverter 2 that outputs DC power as an input of DC power and supplies it to a synchronous motor 3, and detects a motor current. Current detecting unit 3a, a voltage detecting unit 3b for detecting a motor voltage, a rotational position (hereinafter referred to as a rotor position) of a rotor of the synchronous motor 3 and a rotational speed of the rotor (hereinafter referred to as a rotor position) based on the motor current and the motor voltage. (Hereinafter simply referred to as speed), and a speed controller that performs speed control by inputting the speed from the position / speed detector 4 and a speed command given from the outside, and outputs a current command. 5, a phase control unit 6 that performs a phase control by inputting a current command from the speed control unit 5 and a phase command given from the outside and outputs a current amplitude command, The current control unit 7 outputs a voltage command by inputting a current amplitude command, a motor current, and a rotor position (θ) from the control unit 6 and supplies the voltage command to the inverter 2. Of the predetermined maximum current phase (maximum current phase preset corresponding to the motor output voltage and the number of rotations) with the speed and the voltage command from the current control unit 7 as inputs, It has a maximum phase table 8 for outputting a phase, and a phase limiter 9 for limiting a phase command to be supplied to the phase controller 6 based on the maximum current phase.

Examples of the synchronous motor 3 include a permanent magnet motor in which a permanent magnet is disposed inside a rotor (hereinafter referred to as an embedded permanent magnet motor (IPM)). Can be employed.

The maximum phase table 8 may hold the maximum current phase in the form of a function.

The position / speed detector 4 may detect the position and speed of the rotor based on the induced voltage in a non-energized section. The rotor position and speed may be output from the detection result. Of course, it may be one that performs a calculation based on the motor model and outputs the rotor position and speed.

Further, since the configuration of each of the above components is conventionally known, detailed description thereof will be omitted.

First, the current phase-torque characteristics of the IPM will be described.

FIG. 2 is a diagram showing a current phase-torque characteristic of the IPM when the motor current is fixed.

In IPM, since reluctance torque is generated in addition to magnet torque, the maximum torque is generated in a phase advanced from the current phase of 0 degree. At this time, the voltage applied to the IPM decreases as the current phase advances, because it is in a weak field state in which the field of the permanent magnet is weakened.

As can be seen from FIGS. 3A and 3B showing the current phase-torque characteristics when the voltage is fixed, as shown in FIG.
When the applied voltage is constant, the motor current increases but the amount of torque generated with respect to the motor current decreases by advancing the current phase. Then, the IP used for the evaluation in FIG.
At M, the maximum torque is generated when the current phase is 70 to 80 degrees.

The operation of the synchronous motor control device having the above configuration is as follows.

While the synchronous motor 3 is operated by applying the output voltage of the inverter 2, the motor current is detected by the current detecting unit 3a and the motor voltage is detected by the voltage detecting unit 3b. Position the voltage
The rotor position and the speed are detected by supplying the speed to the speed detecting unit 4.

The speed control unit 5 performs speed control based on the detected speed and a speed command given from the outside to generate a current command.

The phase command supplied from the outside is supplied to the phase limit section 9 to limit the phase command so as not to exceed the maximum current phase output from the maximum phase table 8 based on the voltage command and the speed. Of course, when the phase command is smaller than the maximum current phase, the phase command is output as it is.

The phase control unit 6 performs phase control based on the current command from the speed control unit 5 and the phase command from the phase limit unit 9 to output a current amplitude command (and current phase).

The current controller 7 controls the current based on the current amplitude command, the motor current, and the rotor position, and outputs a voltage command to adjust the magnitude and phase of the motor current to the command value. I do.

Therefore, in order to obtain the maximum rotational speed, the current phase is advanced, and in performing the speed control, the current phase is controlled instead of the voltage value, and the maximum torque that the synchronous motor 3 can generate is controlled. Can be controlled.

In the synchronous motor control device having the above-described configuration, the current control unit 7 is omitted, the voltage control unit 5 directly generates the voltage amplitude, the phase control unit 6 performs the voltage phase control, and controls the rotor position. It is possible to configure so as to generate a voltage command to the combined inverter.

FIG. 4 is a block diagram showing another embodiment of the synchronous motor control device of the present invention.

This synchronous motor control device is different from the synchronous motor control device of FIG.
The only difference is that the one that holds the maximum current phase for each speed is adopted.

Accordingly, in this case, the corresponding maximum current phase can be output from the maximum phase table 8 based on the speed from the position / speed detection unit 4 and supplied to the phase limit unit 9.

As a result, similarly to the synchronous motor control device shown in FIG. 1, a process for advancing the current phase to obtain the maximum rotation speed is performed, and in performing the speed control, a process for controlling not the voltage value but the current phase. And control with the maximum torque that can be generated by the synchronous motor 3 can be performed.

In this embodiment, the maximum phase table 8 can be replaced with a constant.

Normally, in a synchronous motor control device having a current control loop, when torque is required, a process for increasing the motor current value is performed, and the current phase is not largely changed. For this reason, it is often necessary to limit the current phase only during the field-weakening control at high speed. Therefore, by employing the synchronous motor control device of this embodiment, the current phase can be limited only when it is really necessary.

FIG. 5 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.

This synchronous motor control device differs from the synchronous motor control device of FIG. 1 only in that a maximum phase holding unit 8 ′ is used instead of the maximum phase table 8.

In the maximum phase holding section 8 ', the maximum current phase that maximizes the motor torque at the inverter maximum output voltage at the time of maximum rotation is set in advance.

Therefore, in this case, the phase limiting section 9 is set based on the maximum current phase from the maximum phase holding section 8 '.
In addition to limiting the phase command, the same operation as the synchronous motor control device of FIG. 1 can be achieved.

As a result, the configuration of the maximum phase holding unit 8 'can be simplified as compared with the maximum phase table 8.

In general, when the voltage is sufficient, the torque is controlled by the current amplitude. Then, when the rotation speed becomes high and the voltage becomes insufficient, the current phase is advanced and the field weakening control is performed. Therefore, the maximum voltage and the maximum phase are obtained at the maximum load. Therefore, there are many applications where there is no problem if the phase is limited with respect to the transient at the time of the maximum voltage and the maximum phase. By applying the synchronous motor control device of this embodiment to these applications, the maximum voltage and the maximum It is possible to limit the phase only for transient changes during the phase.

FIG. 6 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.

The difference between this synchronous motor control device and the synchronous motor control device of FIG.
A point in which the maximum current phase and the minimum current phase immediately before the inverter output current reaches the limit value for each required torque are used in advance, and the output torque is estimated from the current amplitude and the current phase, and the maximum phase table 8 Only in that it further includes a torque estimating unit 10 that supplies the power to the motor.

Therefore, in this case, the torque estimating unit 10 estimates the output torque from the current amplitude and the current phase and supplies the estimated output torque to the maximum phase table 8, from which the output current at that torque is obtained. Read the limited current phase. Then, since the phase limiter 9 limits the phase command by the current phase, it is possible to prevent the disadvantage that the output torque is reduced due to the current limitation acting due to the excessive current phase.

As a result, the phase can be controlled to the maximum while preventing a decrease in torque.

FIG. 7 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.

The difference between this synchronous motor control device and the synchronous motor control device of FIG. 1 is that instead of providing the maximum phase table 8, the current control unit 7 limits the output current when the output current exceeds the limit. And a function having a function of outputting a flag indicating that the output current has been limited.

Therefore, in this case, by supplying a flag from the current control unit 7 indicating that the output current has reached the limit value to the phase limit unit 9, the current phase is prevented from protruding further. It is possible to prevent the disadvantage that the output torque is reduced due to the current limitation acting due to the excessive current phase.

As a result, the phase can be controlled to the maximum while preventing the torque from decreasing.

FIG. 8 is a diagram showing torque-current phase characteristics at the time of voltage and current limitation.

This characteristic shows that the maximum voltage is 200 V,
This was obtained for an IPM with a maximum current of 20 A and a maximum rotation speed of 120 rps.

In the synchronous motor control device of FIG. 4 (claim 2), the line passing at 120 rps and at 70 rps becomes the maximum current phase, and in the synchronous motor control device of FIG. The current phase of the synchronous motor control device shown in FIG. 4 is obtained. In the synchronous motor control device shown in FIG. 5, a vertical line passing through the synchronous motor control device becomes the maximum current phase. In the control device (claim 5), the outside of the line with the current limit of 20 Arms is the range of the current phase to be limited.

Further, it is preferable to determine the maximum current phases and to select the smaller one of the maximum current phases to limit the phase command, thereby preventing the phase command from becoming unnecessarily large. it can.

FIG. 9 is a diagram for explaining the operation phase of the IPM.

If there is a margin in the inverter output voltage during low-speed rotation, the current phase is changed in the order of →→ as the torque increases.

When the inverter output voltage does not flow sufficiently at the operating point of →→ during high-speed rotation, the field is weakened by advancing the phase, and the torque is further increased by increasing the current value. generate. For example, 7
In the case of 0 rps, the operating point of → cannot be taken, so by controlling the current phase in the order of →→,
The maximum torque of the IPM can be extracted.

In a higher-speed region, a region in which the torque is reduced by advancing the current phase occurs in a region smaller than the current limit value (see the right side of 120 rps). In this region, if the phase is advanced in order to generate the torque, the torque decreases conversely, so that the maximum capability of the IPM cannot be exhibited.

In order to avoid this region, the maximum current phase indicated by → should be provided for each rotation speed.
The maximum torque of the IPM can be obtained.

In the above description, the lower limit value of the current phase is set to the maximum torque line, but it is possible to set the lower limit value to the highest efficiency line. However, since the maximum efficiency is about 40 degrees, the lower limit of the current phase can be set to a straight line (constant), and the configuration can be simplified.

FIG. 10 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.

This synchronous motor control device is different from the synchronous motor control device of FIG. 6 in that it further includes a minimum phase table 11 which receives the output torque from the torque estimating unit 10 and that the maximum phase table 8 The maximum current phase from the maximum phase table 8 and the minimum current from the minimum phase table 11 are used in place of the phase limit unit 9 in that a maximum current phase is output using the output torque and the detected speed as inputs. A phase calculation unit 9 'that calculates a current phase by inputting a current phase and a voltage command from the current control unit 7 and outputs the current phase is output as a phase command. The only difference is that the phase controller 6 outputs a current command.

Since the minimum phase table 11 holds a torque-minimum current phase curve to output the minimum current phase, when the torque is applied, the corresponding minimum current phase is output. Specifically, the torque-minimum current phase curve represented by →→ in FIG. 9 is held. However, a fixed value can be used instead.

The maximum phase table 8 holds the maximum current phase due to the current limitation and the maximum current phase for each rotation speed under the voltage constraint. Output. In particular,
The maximum current phase due to the current limitation represented by →→ in FIG. 9 and the maximum current phase for each rotation speed under the voltage constraint represented by → are held.

The phase calculator 9 'controls the phase of the phase command when the voltage command has not reached the maximum voltage, and controls the phase of the phase command when the voltage command has reached the maximum voltage. Then, as a result of the delay control, when the current phase becomes the minimum current phase from the minimum phase table 11, the delay control is stopped and the minimum current phase from the minimum phase table 11 is used as a phase command. Conversely, if the phase advance control results in the maximum current phase from the maximum phase table 8, the phase advance control is stopped and the maximum current phase from the maximum phase table 8 is used as the phase command.

Therefore, in this case, the output torque is estimated by the torque estimating unit 10 based on the current command.
By supplying the maximum phase table 8 and the minimum phase table 11, the maximum current phase from the maximum phase table 8 and the minimum current phase from the minimum phase table 11 are supplied to the phase calculation unit 9 '.

In the phase calculating section 9 ', phase control or phase control is performed between the maximum current phase and the minimum current phase in accordance with whether or not the voltage command has reached the maximum voltage. Output command.

The same operation as that of the synchronous motor control device shown in FIG. 6 can be achieved based on the output phase command.

As a result, the synchronous motor can be controlled by setting the current phase to a value between the maximum current phase and the minimum current phase.

FIG. 11 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.

This synchronous motor control device is different from the synchronous motor control device of FIG. 10 in that it adopts a device that outputs only the speed detected as the maximum phase table 8 and outputs the maximum current phase, and a phase calculation unit. 9 ′, the current phase is calculated by using the maximum current phase from the maximum phase table 8, the minimum current phase from the minimum phase table 11, the current command from the phase control unit 6, and the voltage command from the current control unit 7 as inputs. The only difference is that a signal output as a phase command is employed.

The maximum phase table 8 holds only the maximum current phase for each rotation speed under the voltage constraint.

The phase calculating section 9 'performs the phase control when the current phase is limited by the maximum current phase, and achieves the same operation as the phase calculating section 9' in FIG.

Therefore, also in this case, the synchronous motor can be controlled by setting the current phase to a value between the maximum current phase and the minimum current phase.

It is preferable that the compressor for the air conditioner is driven by a synchronous motor controlled by any of the synchronous motor control devices described above.

In this case, the synchronous motor is cooled by the refrigerant, and a remarkably high cooling efficiency can be achieved. Therefore, it is possible to draw out the limit of the capability of the synchronous motor without particularly considering heat radiation of the synchronous motor.

When the air conditioner compressor is driven by IPM, it is preferable to set the upper limit of the current phase to approximately 60 to 80 degrees.

FIG. 12 is a diagram showing an operation area of the compressor for an air conditioner.

The compressor for an air conditioner does not require an operation at an extremely low speed and an operation at a high speed and a high load, and a constant torque is required at other rotation speeds. For this reason, the maximum current limit is not applied during low-speed operation. Also, there is no influence on the maximum torque current phase at the time of medium speed rotation.

Therefore, by setting the upper limit of the current phase to the maximum torque current phase near the maximum rotational speed, I
It is possible to operate a compressor for an air conditioner by extracting the maximum capacity of PM.

FIG. 13 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.

This synchronous motor control device is different from the synchronous motor control device of FIG. 11 in that a function of outputting a command for drooping the speed on condition that the current limit and the phase limit are reached is further provided as a phase calculating section 9 '. The only difference is that the speed control unit 5 is further provided with a subtraction unit 5a that subtracts a speed drooping command from an externally applied speed command and supplies the speed droop command to the speed control unit 5.

In this case, a speed droop command is output from the phase calculator 9 'on condition that the current limit and the phase limit are reached, and the speed command can be reduced by the subtractor 5a.

The same operation as that of the synchronous motor control device shown in FIG. 11 can be achieved based on the reduced speed command.

As a result, the synchronous motor can be driven below the current limit and the phase limit to prevent the control system from diverging.

A further description will be given.

If the speed droop control is not performed at all, there is a possibility that the synchronous motor can be driven without any inconvenience if the current limit and the phase limit are reached for a moment and the current and the phase are limited. . However, if the current and the phase are constantly limited, the phase error and the current error become P
It accumulates in the internal state of a controller such as an I controller and causes inconvenience such as divergence of a PI controller. In addition, there is a disadvantage that the controller of the speed control system diverges due to the inability to generate the required torque required by the speed control system.

However, if the synchronous motor control device shown in FIG. 13 is adopted, it is possible to prevent the current and phase from being limited by performing the speed droop control, and also to prevent the controller from diverging. it can.

FIG. 14 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.

The synchronous motor control device performs a PI control operation using a difference between a speed command given from the outside and a detected speed as an input, and outputs a current amplitude command,
A phase control unit 6 that performs phase control with a current amplitude command as an input and outputs a current command, a current limiter unit 23 that limits a current with a current command as an input, and a current command and a motor current from the current limiter unit 23. A current control unit 7 that performs a PI control operation using the difference as an input and outputs a voltage command, and a non-interference unit 25 that performs a non-interference process using the voltage command as an input and outputs a d-axis voltage command and a q-axis voltage command , D-q → three-phase converter 26 that converts d-axis voltage command and q-axis voltage command into three-phase voltage commands based on rotor position
A dead time compensating unit 27 that performs dead time compensation by inputting a three-phase voltage command; and a duty limit unit 28 that performs duty limiting by inputting the three-phase voltage command after dead time compensation and outputs a three-phase voltage command. An inverter 2 that generates a three-phase AC voltage by using the three-phase voltage command from the duty limit unit 28 as a control signal and applies it to the synchronous motor 3;
A voltage detection unit 3b for detecting a voltage based on a rotor position with a phase voltage command as an input, a current detection unit 3a for detecting a motor current based on a rotor position, and presetting the detected voltage and motor current as inputs And a position / speed detector 4 for estimating the rotor position and speed based on the motor model thus obtained.

When the output voltage of the inverter 2 reaches the limit, the duty limit unit 28 multiplies the constant K2 by the constant K2 unit 34 to generate a phase advance command.
Outputs an over voltage value to supply to.

The current limiter 23 determines whether or not the current command is equal to or greater than the current limit, and responds to the supply of the current command that is equal to or greater than the current limit to change the current value while maintaining the phase of the current command. An I-term limit command is output in order to reduce the current command to the limit and to fix the internal state integral term (hereinafter referred to as I term) of the speed control unit 5 to a value before the current command reaches the upper limit.

The phase controller 6 controls the phase of the current phase in response to the supply of the phase advance command. When the current phase reaches the upper limit, the phase controller 6 stops the phase advance. An I term limit command is output to fix the I term to a value before the current phase reaches the upper limit.

FIG. 15 is a block diagram showing the configuration of the phase control unit in detail.

A phase control unit 22a for performing phase advance control based on the phase advance command, performing phase control in response to no supply of the phase advance command, and outputting a phase command, A phase lower limit unit 22b that detects that the lower limit value has been reached and supplies a delay control stop command to the phase controller 22a.
And detecting that the phase command has reached the phase upper limit value and supplying a phase control stop command to the phase control unit 22a.
A phase upper limit unit 22c that outputs an I-term limit command, a cos unit 22d that obtains a cos component of the phase command,
a sin section 22e for obtaining an n component, and a first multiplying section 2 for multiplying a cos component by a current amplitude command to output a q-axis current command
2f, and a second multiplying unit 22g for multiplying the sin component by the current amplitude command to output a d-axis current command.

The operation of the synchronous motor control device having the above configuration is as follows.

Until the output voltage of the inverter 2 reaches the limit as the rotation speed of the synchronous motor 3 increases, the inverter 2 is controlled by performing speed control, phase control, current control, etc. Increase the number.

When the output voltage of the inverter 2 reaches the limit as the number of rotations of the synchronous motor 3 increases, a phase advance command is supplied from the duty limit unit 28 to the phase control unit 6, so that the phase control unit At 6, the phase advance control is performed to advance the current phase.

When the current phase reaches the upper limit, a phase advance control stop command is output from the phase upper limit section 22c to stop the phase advance control, and an I term limit command is output to output the internal control in the speed control section 5. Among the states, the I term (integral term) is fixed to a value immediately before the current phase reaches the upper limit.

When the current command exceeds the current limit, the current limiter 23 reduces the current value to the current limit while maintaining the current phase, and outputs an I-term limit command to control the speed. The I term of the internal state in the section 5 is fixed to a value immediately before the current value reaches the current limit.

As a result, the divergence of the speed control unit is prevented,
Stable control of the synchronous motor can be realized.

FIG. 16 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.

This synchronous motor control device is different from the synchronous motor control device of FIG. 13 in that a position / speed detection unit 4 that detects a rotor position and a speed using a motor model is employed. , A waveform generator 12 for generating a waveform pattern in which an arbitrary harmonic component is superimposed according to the rotor position, and a current command to be supplied to the current controller 7 by multiplying the current command by the waveform pattern. The only difference is that the multiplying unit 12a is employed, and that a voltage limiter 13 that clips the voltage command from the current control unit 7 with the inverter output limit voltage is further included.

In this synchronous motor control device, the waveform generator 12 outputs a waveform pattern on which an arbitrary harmonic component is superimposed according to the rotor position. As a result, a voltage command is output.

If this voltage command is equal to or lower than the inverter output limit voltage, it can be supplied to the inverter 3 as it is. However, if the voltage command is larger than the inverter output limit voltage, it is clipped by the voltage limiter 13 at the inverter output limit voltage and supplied to the inverter 3. Is done.

If the voltage command is clipped, the output voltage approaches a rectangular wave, and even if the output limit voltage is the same, the fundamental wave component can be increased, and high-speed rotation can be performed. In such a high-speed range, the mechanical noise becomes larger than the motor noise, and the noise reduction of the motor becomes less meaningful.

In this embodiment, in order to make the voltage waveform closer to a rectangular wave, it is possible to have a characteristic that gradually approaches the output limit voltage. Further, even if the waveform is other than a rectangular wave, the same operation can be achieved by employing a waveform having a high voltage utilization factor.

Furthermore, since arbitrary harmonic components can be superimposed to form a free waveform, noise reduction and the like can be achieved in a low-speed range (current waveform optimization method for brushless DC motor), Shuriri et al. , 1995 IEEJ National Conference on Industrial Applications). Here, if this waveform is set to a sine wave, the harmonic component becomes only the fundamental wave, so that noise and vibration due to harmonics can be easily suppressed.

FIG. 17A shows a state where the voltage command is set to be equal to or lower than the inverter output limit voltage, and the fundamental wave component is also equal to or lower than the inverter output limit voltage.

On the other hand, FIG. 17B shows a state where the voltage command is set to be higher than the inverter output limit voltage. Voltage waveform. As a result, the fundamental wave component can be increased as compared with the case of FIG.

Although FIGS. 17A and 17B show a single-phase case for simplicity of description, the same can be applied to a three-phase case.

FIG. 18 shows the actual measurement results of the operating range by the synchronous motor control device of FIG. 16 (see (A)), the simulation results of the operating range by the synchronous motor control device of FIG. 16 (see (B)), and the voltage limiter. It is a figure showing the simulation result (refer to (C)) of the operation range by the synchronous motor control device which is not used.

As can be seen from FIG. 18, the operating range can be extended to the high speed side by providing the voltage limiter.

The compressor can be driven by a synchronous motor controlled by the synchronous motor control device shown in FIGS.

In general, noise and vibration are a problem in the compressor, and it is necessary to drive the compressor at a high speed. However, by adopting the synchronous motor control device shown in FIGS.
Noise and vibration can be reduced, and driving can be performed at high speed.

FIG. 19 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.

The synchronous motor control device performs a PI control operation using a difference between a speed command given from the outside and a detected speed as an input, and a speed control unit 5 for outputting a current amplitude command;
A phase control unit 6 that performs phase control with the current amplitude command as input, outputs a current command (d-axis current command and q-axis current command), and outputs a phase over value (over value based on a limit phase). , A PI control operation is performed using the difference between the current command and the motor current as an input, and the voltage command (d
A current control unit 7 for outputting a shaft voltage command and a q-axis voltage command), a voltage excess detector 35 for detecting an overvoltage state using the voltage command as an input, and a rotor for receiving a d-axis voltage command and a q-axis voltage command as inputs. A dq → three-phase converter 26 for converting the position into a three-phase voltage command, a duty limiter 28 for performing a duty limit with the three-phase voltage command as input and outputting a three-phase voltage command, and a duty limiter An inverter 2 that generates a three-phase AC voltage and applies it to the synchronous motor 3 using the three-phase voltage command from the control signal 28 as a control signal
A voltage detector 3b for detecting a voltage based on the rotor position by inputting a three-phase voltage command from the duty limit unit 28; a current detector 3a for detecting a motor current based on the rotor position; And a position detecting unit 33 'for estimating the rotor position and the speed by using the motor current as an input.

In order to prevent the current control unit 7 from diverging in response to a large transient current, the duty limit unit 28 has an internal It is possible to configure to output the I term limit command so as to fix the state I term to a value before the voltage command reaches the upper limit.

The phase control section 6 also outputs a phase over value (over value based on the limit phase) and outputs a constant K3
By supplying the value multiplied by the constant K3 by the unit 36 to the subtraction unit 37, the speed command given from the outside is reduced. Therefore, when the current phase exceeds the limit phase due to the phase advance control, the phase over value is multiplied by the constant K3 and subtracted from the speed command, thereby preventing the divergence of the control system.

In the synchronous motor control device having the above configuration, a current amplitude command is generated by the speed control 21 based on the speed difference, and a phase control is performed by the phase control unit 6 to generate a current command.

Then, based on the difference between the current command from the phase control unit 6 and the detected motor current, a voltage command is generated by the current control unit 7 to control the motor output voltage.

When the rotation speed increases and the motor induced voltage increases to reach the inverter output limit voltage, the current control unit 7
Cannot output the voltage command output by the inverter 2 completely, and the duty is 1 at the peak of the output voltage.
Beyond 00%, the output voltage is clamped.

However, when only the peak of the output voltage is clamped and the duty does not exceed 100%, voltage control is possible. For this reason, the current control unit 7 does not diverge immediately, and can perform current control on average even if the output voltage has a rectangular waveform.

As a result, even when the amplitude of the inverter output voltage increases and voltage clamping occurs, the motor current can be controlled.

FIG. 20 shows a conventional synchronous motor control device for comparison with the synchronous motor control device of FIG.

A synchronous motor control device shown in FIG. 20 includes a converter 1a which receives an AC power supply 1 as an input and outputs DC power,
DC power is input and AC power is output.
, A current detector 3a for detecting a motor current, and a voltage detector 3b for detecting a motor voltage
And a position / speed detector 4 for detecting a rotor position and a speed by inputting a motor current and a motor voltage; a speed command given from the outside; and a speed control by inputting a rotor position and a speed from the position / speed detector 4 as inputs. Speed control unit 5 that outputs a current command or a voltage command by performing a current control, a current control unit 7 that performs current control using the current command and the motor current from the speed control unit 5 as inputs, and outputs a voltage command, and a speed control unit. A selection unit 15 for selecting a voltage command from the control unit 5 or a voltage command from the current control unit 7; a voltage command selected by the selection unit 15 as an input; clipping at an inverter output limit voltage; and outputting a voltage saturation signal. A voltage limiter 13 and a switching determination unit 14 that performs switching determination by using a voltage saturation signal as an input and supplies the switching signal to the speed control unit 5 and the selection unit 15. Which comprise.

This synchronous motor control device has a current control loop and uses the output voltage of the inverter until it is full. In performing the control in which the voltage clamp occurs, the operation of the current control minor loop is stopped at the time of the voltage clamp to reduce the voltage. Perform control.

Therefore, when a voltage clamp occurs, the motor current cannot be controlled. As a result,
If the current increases due to disturbance or the like at the time of voltage clamping, current control cannot be performed, causing a disadvantage that the synchronous motor or the inverter is destroyed.

As can be seen by comparing with the synchronous motor control device of FIG. 20, the adoption of the synchronous motor control device of FIG. 19 makes it possible to control the current And the destruction of the synchronous motor and the inverter can be prevented.

FIG. 21 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.

This synchronous motor control device performs a PI control operation with a difference between a speed command given from the outside and a detected speed as an input, and a speed control unit 5 for outputting a current amplitude command;
A phase control unit 6 that performs phase control with a current amplitude command as input and outputs a current command, a current excess detector 38 that detects a current excess state with the current command as input, and outputs a current over value, and a current excess detection Current limiter 23 that limits the current when the current command from input device 38 is input.
And a current control unit 7 that performs a PI control operation by using a difference between the current command from the current limiter unit 23 and the motor current as an input and outputs a voltage command. A non-interference unit 25 that outputs a voltage command and a q-axis voltage command, a voltage excess detector 35 that detects a voltage excess state by receiving a d-axis voltage command and a q-axis voltage command, and outputs a voltage over value, An overmodulation gain correction unit 39 that performs a correction based on an overmodulation gain by using the d-axis voltage command and the q-axis voltage command from the detector 35 as inputs,
A dq → three-phase converter 26 that converts the d-axis voltage command and the q-axis voltage command from the overmodulation gain correction unit 39 into a three-phase voltage command based on the rotor position, and receives the three-phase voltage command as an input. A dead time compensating unit 27 for performing dead time compensation, a duty limit unit 28 for performing a duty limit by inputting a three-phase voltage command after dead time compensation and outputting a three-phase voltage command, and a three-phase An inverter 2 that generates a three-phase AC voltage using the voltage command as a control signal and applies the voltage to the synchronous motor 3;
A voltage detector 3b for detecting a voltage based on the rotor position with a three-phase voltage command from the duty limit unit 28 as an input, a current detector 3a for detecting a motor current based on the rotor position, a detected voltage and a motor And a position / speed detecting unit 4 for estimating a rotor position and a speed based on a motor model set in advance by using the current as an input.

The voltage excess detector 35 detects the degree of overmodulation (for example, a phase voltage command before clamping / a phase voltage after clamping), and is multiplied by a constant K2 by a constant K2 unit 34 to perform a phase advance command. And outputs an overvoltage value to be supplied to the phase control unit 6.

The current limiter 23 determines whether the current command is at or above the current limit, and responds to the supply of the current command at or above the current limit to change the current value while maintaining the phase of the current command. An I-term limit command is output to reduce the limit to the limit and to fix the internal term I of the speed control unit 5 to a value before the current command reaches the upper limit.

The duty limiter 28 determines that the duty is limited (for example, when the duty is 1).
00%), an I-term limit command is output to fix the internal term I of the current control unit 7 to a value before the voltage reaches the upper limit.

The phase control section 6 controls the current phase in advance in response to the supply of the phase advance command, stops the phase advance when the current phase reaches the upper limit, and sets the constant K3 by the constant K3 section 36. And outputs a phase over value to be supplied to the subtraction unit 37 as a deceleration command. Specifically, for example,
The phase control unit 6 is configured by the configuration shown in FIG.

In response to the detection of the excess current state, the excess current detector 38 uses the constant K1
The output value is multiplied by 1 to output an overcurrent value to be supplied to the subtraction unit 37 as a deceleration command.

When the synchronous motor control device having this configuration is adopted, the speed control by the speed control unit 5 and the phase control unit 6
When the inverter 2 is controlled by performing the phase control by the current control unit 7 and the current control by the current control unit 7, and the synchronous motor 3 is driven, a voltage command exceeding the inverter output limit voltage is supplied to the duty limit unit 28. In addition, since the voltage command is clamped, the output voltage command decreases. However, in this synchronous motor control device, the overmodulation gain correction unit 39 amplifies the voltage amplitude to compensate for the decrease in the voltage command due to the clamp, so that the decrease in the voltage command can be compensated. It is possible to compensate for a decrease in torque due to a decrease in the voltage command.

The voltage correction coefficient in the overmodulation gain correction section 39 is set as shown in FIG. 22, for example, when the output waveform before clamping is a sine wave. For example,
A voltage correction coefficient may be provided as a table, or an expression representing the voltage correction coefficient may be provided.

Therefore, by selecting a voltage correction coefficient according to the command voltage and multiplying the command voltage, a corrected voltage command can be obtained.

The voltage correction coefficient shown in FIG. 22 corresponds to the single-phase case, and is obtained by plotting the ratio between the fundamental wave of the command voltage and the clamped fundamental wave. Of course, it can be easily calculated in the same manner in the case of three phases.

FIG. 23 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.

This synchronous motor control device differs from the synchronous motor control device of FIG. 21 in that the non-interference section 25, the overmodulation gain correction section 39, and the dead time compensation section 27 are omitted, and the observer section 33 is replaced. The only difference is that a position detection unit 33 'for detecting the rotor position and the speed by using the motor current and the motor voltage as inputs is employed.

When the synchronous motor control device having this structure is employed, the speed control by the speed control unit 5 and the phase control unit 6
And the current control by the current control unit 7 to control the inverter 2 and, while the synchronous motor 3 is being driven, to detect the degree of overmodulation by the voltage excess detector 35 and obtain a constant K2 unit 34 Through the phase controller 6
Give feedback to.

The phase control section 6 delays the current phase when the degree of overmodulation is lower than a predetermined value, and finally obtains a desired current phase such as a current phase corresponding to the maximum efficiency or the maximum torque. On the contrary, when the degree of overmodulation is equal to or greater than a predetermined value, the current phase is advanced, the motor induced voltage is reduced by the field weakening control, and the degree of overmodulation is reduced, so that the degree of overmodulation is set to a desired value. can do.

The synchronous motor controlled by the synchronous motor control device shown in FIG. 19, FIG. 21, or FIG.
It is preferable to employ PM. In this case, IPM
And the field-weakening control can be performed effectively.

Further, it is preferable to drive the compressor by a synchronous motor controlled by the synchronous motor control device shown in FIG. 19, FIG. 21, or FIG.

Conventionally, there has been a demand for compressors to use the inverter output voltage to its limit in order to emphasize efficiency. Therefore, conventionally, the synchronous motor has been driven by voltage control.

Generally, in a compressor for an air conditioner or a refrigerator, a sudden increase in load occurs due to the suction of a liquid refrigerant or the like. At this time, if the current control is not performed, there is a high risk that the synchronous motor or the inverter will be damaged by an excessive current. Conventionally, protection by hardware has been performed to solve such inconvenience.However, in this case, the compressor is completely stopped at the time of overcurrent, and it takes time to restart the compressor. Because the temperature cannot be adjusted, the comfort is impaired.

However, if the synchronous motor control device shown in FIG. 23 is employed, current control can be performed even in the case described above. As a result, the inverter voltage can be reduced to the limit while preventing the synchronous motor and the inverter from being damaged. Since the synchronous motor can be driven by utilizing this, it is possible to prevent a decrease in comfort or the like due to the stoppage of the compressor.

[0248]

According to the first aspect of the present invention, when the current phase is advanced to increase the maximum rotational speed, or when the voltage phase or the current phase is manipulated to control the speed, the synchronous motor can generate a torque near the maximum torque. Control and prevent trips from occurring, and make the best use of voltage and current, thereby achieving maximum efficiency through downsizing and optimal tuning of synchronous motors. It has a unique effect that it can be performed.

According to the second aspect of the present invention, the synchronous motor can be controlled by using the upper limit of the current phase set for each speed, and the current phase in the field-weakening control at a high speed is kept below the upper limit. In addition to being able to prevent trips from occurring, it is possible to maximize the use of voltage and current, and in addition, it is possible to reduce the size of synchronous motors and achieve maximum efficiency through optimal tuning. Has the effect of

The third aspect of the invention has the same effect as the first or second aspect.

According to the fourth aspect of the present invention, the processing can be simplified, the occurrence of a trip can be prevented beforehand, the voltage and current can be used to the maximum, and the size of the synchronous motor can be reduced, and the optimum tuning can be achieved. This has a specific effect that the maximum efficiency can be realized.

According to the fifth aspect of the present invention, torque reduction is prevented,
Moreover, the current phase can be controlled to the maximum, and the occurrence of a trip can be prevented beforehand, and the voltage and current can be used to the maximum. The specific effect that maximum efficiency can be achieved is achieved.

According to the sixth aspect of the present invention, by limiting the current phase by the selected upper limit value, it is possible to prevent the occurrence of a trip beforehand, to make the most of the voltage and current, and to achieve the synchronous operation. There is a special effect that the motor can be downsized and the maximum efficiency can be achieved by the optimal tuning.

According to the invention of claim 7, the current phase can be controlled to a phase between the lower limit value and the upper limit value, and the same effect as any of claims 1 to 6 can be obtained.

According to the eighth aspect of the present invention, it is possible to cool the synchronous motor, which generates a large amount of heat during the field-weakening control, by the refrigerant, and without particularly considering heat radiation of the synchronous motor, as in any one of the first to seventh aspects. Has the effect of

According to the ninth aspect of the present invention, good controllability can be realized by extracting the maximum capacity of the permanent magnet motor.
Moreover, the same effects as those of the eighth aspect can be obtained.

According to the tenth aspect of the present invention, the divergence of the control system can be prevented by driving the permanent magnet motor below the current limit and the phase limit. Is maximized, and as a result, a unique effect is achieved in that the size of the synchronous motor can be reduced and the maximum efficiency can be achieved by optimal tuning.

According to the eleventh aspect of the present invention, the divergence of the speed control system can be prevented, the occurrence of a trip can be prevented beforehand, and the voltage and current can be used to the maximum extent. There is a special effect that the motor can be downsized and the maximum efficiency can be achieved by the optimal tuning.

According to the twelfth aspect of the present invention, by appropriately adjusting the voltage waveform, noise can be reduced in a low-speed region, and the high-speed operation range can be expanded. An effect similar to that of the eleventh embodiment is obtained.

According to a thirteenth aspect of the present invention, noise caused by harmonics,
Vibration can be easily suppressed and the same effects as those of the twelfth aspect can be obtained.

According to the fourteenth aspect, it is possible to achieve a sufficient expansion of the high-speed operation range, and it has the same effect as the twelfth or thirteenth aspect.

According to the fifteenth aspect of the present invention, noise and vibration can be reduced, the drive can be performed at a high speed, and the same effects as any one of the tenth to fourteenth aspects can be obtained.

According to the sixteenth aspect of the present invention, the motor current can be controlled even when the current increases due to disturbance or the like at the time of voltage limitation, and the occurrence of a trip can be prevented beforehand. In addition, there is a specific effect that the synchronous motor can be downsized and the maximum efficiency can be realized by the optimal tuning.

The seventeenth invention has the same effect as the sixteenth invention.

According to the eighteenth aspect of the present invention, the same effect as that of the sixteenth or seventeenth aspect can be obtained, in addition to maintaining the torque before the current limitation.

The nineteenth aspect has the same effect as the eighteenth aspect.

According to the twentieth aspect, it is possible to prevent the degree of overmodulation from becoming too large, and to achieve the same effect as any one of the sixteenth to nineteenth aspects.

According to the twenty-first aspect of the present invention, the field weakening action can be effectively used, and the ninth to the second aspects of the present invention can be applied.
0 has the same effect.

According to the twenty-second aspect of the present invention, even if a sudden increase in load occurs, it is possible to prevent an overcurrent that may cause damage to the synchronous motor and the inverter, and to achieve the first aspect.
The same effect as any one of claims 6 to 21 is achieved.

According to a twenty-third aspect of the present invention, when the current phase is advanced to increase the maximum rotation speed, or when the voltage phase or the current phase is manipulated to control the speed, the control near the maximum torque that the synchronous motor can generate is performed. Can be performed, and furthermore, the occurrence of a trip can be prevented beforehand, and the voltage and current can be used to the utmost, so that the maximum efficiency can be realized by downsizing and optimal tuning of the synchronous motor. It has a unique effect.

According to a twenty-fourth aspect of the present invention, the synchronous motor can be controlled by using the upper limit value of the current phase set for each speed, and the current phase in the field-weakening control at high speed is kept below the upper limit value. In addition to being able to prevent trips from occurring, it is possible to maximize the use of voltage and current, and in addition, it is possible to reduce the size of synchronous motors and achieve maximum efficiency through optimal tuning. Has the effect of

The invention of claim 25 has the same effect as that of claim 23 or claim 24.

According to the twenty-sixth aspect, the configuration is simplified.
It is possible to prevent the occurrence of a trip beforehand, to maximize the use of the voltage and the current, and to achieve the specific effects of achieving downsizing of the synchronous motor and realizing the maximum efficiency by the optimal tuning.

According to the twenty-seventh aspect, torque reduction can be prevented, current phase can be controlled to the maximum, trips can be prevented from occurring, and voltage and current are used to the maximum. As a result, it is possible to reduce the size of the synchronous motor and to achieve the maximum efficiency by optimal tuning.

According to the twenty-eighth aspect of the present invention, by limiting the current phase by the selected upper limit value, it is possible to prevent the occurrence of a trip, to maximize the use of the voltage and the current, and to achieve the synchronization. Motor downsizing,
In addition, a special effect that the maximum efficiency can be achieved by the optimal tuning is achieved.

According to the invention of claim 29, the current phase can be controlled to a phase between the lower limit value and the upper limit value, and the same effect as any one of claims 23 to 28 can be obtained.

According to the thirtieth aspect, the synchronous motor can be cooled by the refrigerant, and the same effect as any one of the twenty-third to the twenty-ninth aspect can be obtained without particularly considering heat radiation of the synchronous motor.

According to the invention of the thirty-first aspect, the maximum performance of the permanent magnet motor can be obtained to achieve good operating characteristics, and the same effect as that of the thirty-third aspect can be obtained.

The invention according to claim 32 is capable of preventing the divergence of the control system by driving the permanent magnet motor below the current limit and the phase limit, and furthermore, it is possible to prevent the occurrence of a trip beforehand and to reduce the voltage and current. Is maximized, and as a result, a unique effect is achieved in that the size of the synchronous motor can be reduced and the maximum efficiency can be achieved by optimal tuning.

According to the thirty-third aspect of the present invention, the divergence of the speed control system can be prevented, trips can be prevented from occurring, and the voltage and current can be used to the maximum extent. It is unique in that it can achieve maximum efficiency through miniaturization and optimal tuning.

According to the thirty-fourth aspect of the present invention, by appropriately adjusting the voltage waveform, it is possible to achieve a quiet operation in a low-speed range and to achieve an expansion of a high-speed operation range. It has the same effect as 33.

The invention according to claim 35 is characterized in that noise due to harmonics,
Vibration can be easily suppressed and the same effects as those of the thirty-fourth aspect can be obtained.

According to the invention of claim 36, a sufficient expansion of the high-speed operation range can be achieved, and the same effects as those of claim 34 or claim 35 are obtained.

According to the thirty-seventh aspect of the present invention, it is possible to reduce noise and vibration, drive at a high speed, and achieve the same effects as any of the thirty-second to thirty-sixth aspects.

According to the thirty-eighth aspect of the present invention, it is possible to control the motor current even when the current increases due to disturbance or the like at the time of voltage limitation, to prevent a trip from occurring, and to maximize the voltage and current. In addition, there is a specific effect that the synchronous motor can be downsized and the maximum efficiency can be realized by the optimal tuning.

The thirty-ninth aspect has the same effect as the thirty-eighth aspect.

According to the fortieth aspect, the torque before the current limitation can be maintained, and the same effect as that of the thirty-eighth or thirty-ninth aspect can be obtained.

The invention of claim 41 has the same effect as claim 40.

According to the invention of claim 42, it is possible to prevent the degree of overmodulation from becoming too large, and it has the same effect as any of claims 38 to 41.

According to the invention of claim 43, in addition to being able to effectively use the field weakening effect, the same effect as any of claims 31 to 42 is obtained.

According to the forty-fourth aspect of the present invention, even when a sudden increase in load occurs, it is possible to prevent an overcurrent that may cause damage to the synchronous motor and the inverter, and to achieve the third aspect.
The same effect as any one of claims 8 to 43 is achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a synchronous motor control device according to the present invention.

FIG. 2 is a diagram showing a current phase-torque characteristic of an IPM when a motor current is fixed.

FIG. 3 is a diagram showing a current phase-torque characteristic when a voltage is fixed.

FIG. 4 is a block diagram showing another embodiment of the synchronous motor control device of the present invention.

FIG. 5 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.

FIG. 6 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.

FIG. 7 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.

FIG. 8 is a diagram showing torque-current phase characteristics at the time of voltage and current limitation.

FIG. 9 is a diagram illustrating an operation phase of the IPM.

FIG. 10 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.

FIG. 11 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.

FIG. 12 is a diagram showing an operation area of the compressor for an air conditioner.

FIG. 13 is a block diagram showing still another embodiment of the synchronous motor control device of the present invention.

FIG. 14 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.

FIG. 15 is a block diagram showing a configuration of a phase control unit in detail.

FIG. 16 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.

FIG. 17 is a diagram illustrating a state where the voltage command is set to be equal to or lower than the inverter output limit voltage, and a diagram illustrating a state where the voltage command is set to be higher than the inverter output limit voltage.

18 shows an actual measurement result of an operation range by the synchronous motor control device of FIG. 16, a simulation result of an operation range by the synchronous motor control device of FIG. 16, and a simulation result of an operation range by a synchronous motor control device not using a voltage limiter. FIG.

FIG. 19 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.

FIG. 20 is a block diagram showing a conventional synchronous motor control device.

FIG. 21 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.

FIG. 22 is a diagram illustrating an example of a voltage correction coefficient-command voltage characteristic.

FIG. 23 is a block diagram showing a main part of still another embodiment of the synchronous motor control device of the present invention.

[Explanation of symbols]

 2 Inverter 3 Synchronous motor 5 Speed control unit 5a Subtraction unit 6 Phase control unit 7 Current control unit 8 Maximum phase table 8 'Maximum phase holding unit 9 Phase limit unit 9' Phase calculation unit 11 Minimum phase table 12 Waveform generation unit 12a Multiplication unit 13 voltage limiter 35 overvoltage detector 39 overmodulation gain correction unit

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Masanobu Kita 1000-2, Oya, Okamotocho, Kusatsu-shi, Shiga F-term in Daikin Air Conditioning Technology Laboratory Co., Ltd. 5H560 AA02 BB04 BB12 DA13 DB13 DC03 EB01 EB07 EC02 GG00 JJ02 RR01 SS07 UA02 XA02 XA04 XA05 XA13 5H576 AA10 BB02 BB03 BB04 DD07 EE01 EE11 FF07 FF08 GG04 GG05 GG06 HB02 JJ04 JJ17 JJ24 JJ25 JJ28 LL14 LL15 LL16 LL22 LL24 LL38 LL39 LL38

Claims (44)

[Claims] 1. A synchronous motor control method for controlling a synchronous motor (3) by supplying an output voltage of an inverter (2) to a synchronous motor (3), wherein an upper limit value of a current phase is set for each instant. A synchronous motor control method, wherein the phase is set at or near the phase at which the motor torque is maximized at the inverter output voltage. 2. A synchronous motor control method for controlling a synchronous motor (3) by supplying an output voltage of an inverter (2) to a synchronous motor (3), wherein an upper limit value of a current phase is set for each rotation speed. A synchronous motor control method, wherein the phase is set at or near the phase at which the motor torque is maximized at the inverter maximum output voltage. 3. The synchronous motor control method according to claim 1, wherein the upper limit value of the current phase is changed at least in response to a rotation speed. 4. A synchronous motor control method for controlling a synchronous motor (3) by supplying an output voltage of an inverter (2) to the synchronous motor (3). A synchronous motor control method, wherein the phase is set at or near the phase at which the motor torque is maximized at the maximum output voltage. 5. A synchronous motor control method for controlling a synchronous motor (3) by supplying an output voltage of an inverter (2) to a synchronous motor (3), wherein a current phase limit value is determined for each required torque by an inverter output. The maximum and minimum phases at which the current will be limited,
Alternatively, the synchronous motor control method is set near the above. 6. A synchronous motor control method for controlling a synchronous motor (3) by supplying an output voltage of an inverter (2) to a synchronous motor (3), wherein an upper limit value of a current phase is set for each instant. A synchronous motor control method, wherein the smallest upper limit value is selected from the upper limit values set by claim 1, claim 2, claim 4, and claim 5. 7. The synchronous motor is driven by setting a lower limit value of a current phase to a current phase that maximizes efficiency or torque, or a current phase near the maximum, and drives a synchronous motor with the smallest current phase among current phases that can output required torque. Items 1 to 6
The synchronous motor control method according to any one of the above. 8. The synchronous motor control method according to claim 1, wherein the air conditioner compressor is driven by the synchronous motor (3). 9. The synchronous motor control method according to claim 8, wherein the synchronous motor is a permanent magnet motor, and sets an upper limit of a current phase to approximately 60 degrees to 80 degrees. 10. A synchronous motor control method for controlling a permanent magnet motor by supplying an output voltage of the inverter (2) to a permanent magnet motor, wherein the output voltage of the inverter (2) is increased to a limit value as the rotation speed increases. A synchronous motor control method comprising: advancing a current phase in response to reaching a current limit value; and performing speed droop control in response to reaching a predetermined current phase limit value or a current limit value. 11. A synchronous motor control method for controlling a permanent magnet motor by supplying an output voltage of the inverter (2) to a permanent magnet motor, wherein the output voltage of the inverter (2) is increased to a limit value as the rotation speed increases. The current phase is advanced in response to reaching the limit, and the internal state of the speed control means is maintained in a state immediately before the limit value is reached in response to reaching the predetermined current phase limit value or the current limit value. Synchronous motor control method. 12. When the inverter output voltage has a margin with respect to the output voltage limit value, a desired voltage waveform is output from the inverter (2), and in response to the inverter output voltage approaching the output voltage limit value. 12. The synchronous motor control method according to claim 10, wherein an output voltage waveform from the inverter (2) is made closer to an output voltage waveform having a high voltage utilization rate. 13. The synchronous motor control method according to claim 12, wherein a sine wave is adopted as the desired voltage waveform. 14. The synchronous motor control method according to claim 12, wherein a rectangular wave is employed as the output voltage waveform having a high voltage utilization factor. 15. The synchronous motor control method according to claim 10, wherein the compressor is driven by a permanent magnet motor. 16. A synchronous motor control method for controlling a synchronous motor (3) by supplying an output voltage of an inverter (2) to a synchronous motor (3), regardless of whether the inverter output voltage amplitude is limited. And controlling the motor current. 17. The motor current control according to claim 16, wherein the motor terminal voltage command value is increased in response to a small motor current, and the motor terminal voltage command value is decreased in response to a large motor current. 2. The synchronous motor control method according to 1. 18. The synchronous motor control method according to claim 16, wherein the inverter (2) is controlled to compensate for a decrease in torque due to the voltage limitation. 19. The synchronous motor control method according to claim 18, wherein the reduction of the torque is compensated for by the reduction of the amplitude of the fundamental wave component of the phase voltage command due to the voltage limitation. 20. The method according to claim 16, wherein the current phase is controlled so that the degree of overmodulation becomes a predetermined value in response to the degree of overmodulation for increasing the voltage utilization rate exceeding a predetermined value. 20. The method of controlling a synchronous motor according to any one of the nineteenth aspects. 21. The synchronous motor control method according to claim 9, wherein the synchronous motor (3) is a permanent magnet motor having a permanent magnet embedded inside a rotor. 22. The synchronous motor control method according to claim 16, wherein the compressor is driven by the synchronous motor (3). 23. A synchronous motor control device for controlling a synchronous motor (3) by supplying an output voltage of an inverter (2) to a synchronous motor (3), wherein an upper limit value of a current phase is set for each instant. Inverter control means (6) (7) for setting at or near the phase that maximizes the motor torque at the inverter output voltage
(8) A synchronous motor control device including (8 '), (9), (9'), and (11). 24. A synchronous motor control device for controlling a synchronous motor (3) by supplying an output voltage of an inverter (2) to a synchronous motor (3), wherein an upper limit value of a current phase is set for each rotation speed. Inverter control means (6) (7) for setting at or near the phase at which the motor torque is maximized at the inverter maximum output voltage
(8) A synchronous motor control device including (8 '), (9), (9'), and (11). 25. The synchronous motor control device according to claim 23, wherein the inverter control means (8) changes an upper limit value of a current phase at least in response to a rotation speed. 26. A synchronous motor control device for controlling a synchronous motor (3) by supplying an output voltage of an inverter (2) to a synchronous motor (3). Inverter control means (6) (7) for setting the phase at or near the phase that maximizes the motor torque at the maximum output voltage
(8) A synchronous motor control device including (8 '), (9), (9'), and (11). 27. A synchronous motor control device for controlling a synchronous motor (3) by supplying an output voltage of an inverter (2) to a synchronous motor (3), wherein a current phase limit value is determined for each required torque by an inverter output. The maximum and minimum phases at which the current will be limited,
Alternatively, a synchronous motor control device including inverter control means (6), (7), (8), (9), (9 '), and (11) set near these. 28. A synchronous motor control device for controlling a synchronous motor (3) by supplying an output voltage of an inverter (2) to a synchronous motor (3), wherein an upper limit value of a current phase is set for each instant. 28. A synchronous motor control device comprising an inverter control means for selecting the smallest upper limit value from the upper limit values set by claim 23, claim 24, claim 26, and claim 27. 29. The inverter control means (6) (7).
(8) (9 ′) and (11) set the lower limit of the current phase to the current phase that maximizes the efficiency or the torque, or the vicinity thereof, and set the lower limit of the current phase that can output the required torque. 23. The method according to claim 23, wherein the inverter controls the inverter to drive the synchronous motor.
8. The synchronous motor control device according to any one of 8. 30. The synchronous motor (3) for driving a compressor for an air conditioner.
10. The synchronous motor control device according to any one of items 9. 31. The synchronous motor (3) is a permanent magnet motor, and the inverter control means (6) (7) (8)
31. The synchronous motor control device according to claim 30, wherein (9) sets the upper limit value of the current phase to approximately 60 degrees to 80 degrees. 32. A synchronous motor control device for controlling a permanent magnet motor by supplying an output voltage of the inverter (2) to a permanent magnet motor, wherein the output voltage of the inverter (2) is increased to a limit value as the rotation speed increases. Inverter control means (5) (5) for performing a current droop control in response to reaching a predetermined current phase limit value or a current limit value in response to reaching a predetermined current phase limit value.
a) (6) (7) (8) (9 ′) (10) (11) (1
3) A synchronous motor control device comprising: 33. A synchronous motor control device for controlling a permanent magnet motor by supplying an output voltage of the inverter (2) to a permanent magnet motor, wherein the output voltage of the inverter (2) is increased to a limit value as the rotation speed increases. In response to reaching the limit, the current phase is advanced, and in response to reaching the predetermined current phase limit value or the current limit value, the internal state of the speed control means (5) is maintained at the state immediately before reaching the limit value. Inverter control means (5) (6) (7)
(8) A synchronous motor control device including (9) and (13). 34. The inverter control means (5) (7).
(12) (12a) and (13) output a desired voltage waveform from the inverter (2) when the inverter output voltage has a margin with respect to the output voltage limit value, and the inverter output voltage approaches the output voltage limit value. 34. The method according to claim 32, wherein the output voltage waveform from the inverter (2) is made closer to an output voltage waveform having a high voltage utilization rate in response to the operation.
3. The synchronous motor control device according to 3. 35. The inverter control means (5) (7).
35. The synchronous motor control device according to claim 34, wherein (12), (12a) and (13) adopt a sine wave as the desired voltage waveform. 36. The inverter control means (5) (7).
36. The synchronous motor control device according to claim 34 or claim 35, wherein (12) and (13) adopt a rectangular wave as the output voltage waveform having a high voltage utilization rate. 37. The synchronous motor control device according to claim 32, wherein the permanent magnet motor drives a compressor. 38. A synchronous motor control device for controlling a synchronous motor (3) by supplying an output voltage of an inverter (2) to a synchronous motor (3), regardless of whether an inverter output voltage amplitude is limited. And inverter control means (6) (7) (35) (39) for controlling the inverter (2) to control the motor current.
A synchronous motor control device comprising: 39. The inverter control means (6) (7).
(35) and (39) control the motor current by increasing the motor terminal voltage command value in response to a small motor current and decreasing the motor terminal voltage command value in response to a large motor current. 39. The synchronous motor control device according to claim 38, wherein the control is performed by: 40. The inverter control means (6) (3)
5) The synchronous motor control device according to claim 38 or 39, wherein (39) controls the inverter (2) to compensate for a decrease in torque due to the voltage limitation. 41. The inverter control means (6) (3)
5) The synchronous motor control device according to claim 40, wherein (39) performs the compensation for the decrease in the torque by compensating for the decrease in the amplitude of the fundamental wave component of the phase voltage command due to the voltage limitation. 42. The inverter control means (6) (3)
The method according to claim 38, wherein in response to the fact that the degree of overmodulation exceeds a predetermined value, the current phase is controlled so that the degree of overmodulation becomes a predetermined value. A synchronous motor control device according to any one of the above. 43. The synchronous motor control device according to claim 31, wherein the synchronous motor (3) is a permanent magnet motor having a permanent magnet embedded inside a rotor. 44. The synchronous motor control device according to claim 38, wherein the synchronous motor (3) drives a compressor.